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Author Topic: cb750f cam/valve spring question  (Read 1050 times)

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Offline bucky katt

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cb750f cam/valve spring question
« on: March 05, 2010, 04:19:56 PM »
i'm getting a 77 750f cam and i'm wondering if i should get new valve springs for it. this is going into a 76 k head. i have had this motor to over 10k rpms before with no valve float at all.
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Of all God's creatures there is only one that cannot be made the slave of the lash. That one is the cat. If man could be crossed with the cat it would improve man, but it would deteriorate the cat.
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Offline TwoTired

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Re: cb750f cam/valve spring question
« Reply #1 on: March 05, 2010, 04:41:33 PM »
Higher lift cams need heavier springing at the same RPMs as before.

Heavier springs usually need better retainers for high RPM use.

What was the spring weight for the 750F cam compared to what you had/have?
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Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

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Offline bucky katt

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Re: cb750f cam/valve spring question
« Reply #2 on: March 05, 2010, 04:42:41 PM »
no idea, this is a stock 75 750f cam thats in the bike now with stock 76 k springs
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Of all God's creatures there is only one that cannot be made the slave of the lash. That one is the cat. If man could be crossed with the cat it would improve man, but it would deteriorate the cat.
Mark Twain - Notebook, 1894

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: cb750f cam/valve spring question
« Reply #3 on: March 05, 2010, 10:03:37 PM »
Fuzzy Buck,

You can't go wrong with stronger springs. You can go wrong with stock springs. As I've alluded to many times, missed 2nd on power shift and the 75 750F engine was history. The valve didn't want to return at the correct moment. BIG hole in the top of the piston. Rebuilt with Yoshi 812 and       S & W springs. Stock springs made it almost 6000 miles. S & W have 24,000+ and the 812 pistons are still intact and I haven't taken it easy on it since! If it gets started it sees top of the redline. Insurance.
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As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline bucky katt

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Re: cb750f cam/valve spring question
« Reply #4 on: March 05, 2010, 10:14:16 PM »
i wont have the money for springs and retainers until the end of the year most likely, unless i can get a bunch of stuff sold. thats about 350 dollars isnt it?
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Of all God's creatures there is only one that cannot be made the slave of the lash. That one is the cat. If man could be crossed with the cat it would improve man, but it would deteriorate the cat.
Mark Twain - Notebook, 1894

Offline bucky katt

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Re: cb750f cam/valve spring question
« Reply #5 on: March 06, 2010, 06:52:56 AM »
okay i got the old home audio cd player sold so now i have the money for the valve springs from APE, the next question is can i use the stock retainers with them since i cant see having the 149 dollars for retainers anytime soon. i have retainers from a 76k head as well as a 75 750f head.
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Of all God's creatures there is only one that cannot be made the slave of the lash. That one is the cat. If man could be crossed with the cat it would improve man, but it would deteriorate the cat.
Mark Twain - Notebook, 1894

Offline Whaleman

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Re: cb750f cam/valve spring question
« Reply #6 on: March 06, 2010, 06:54:29 AM »
Sell some cats! Dan
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: cb750f cam/valve spring question
« Reply #7 on: March 06, 2010, 09:06:26 AM »
I've been using my stock retainers. The main advantage of Titanium retainers is lighter valve train weight. The second advantage of Titanium retainers is they look cool  8)
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As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline bucky katt

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Re: cb750f cam/valve spring question
« Reply #8 on: March 06, 2010, 09:12:11 AM »
cool, i'm ordering my springs monday, i now have my top end taken care of. suddenly all of my craigslist ads are creating results. i just sold the old cd changer and i'm meeting up with someone tonight to get rid of the telecaster i recently got (i just dont like the feel and sound) trading it for a pretty nice ibanez acoustic/electric 6 string. tomorrow i'm picking up 400 vinyl lps about half still in their shrink wrap for 25 dollars. and monday afternoon i think i'm going to be selling the slightly modified mobile cb (modified without an amp it'll swing to 28 watts through a little wil magnet mount antenna)
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Of all God's creatures there is only one that cannot be made the slave of the lash. That one is the cat. If man could be crossed with the cat it would improve man, but it would deteriorate the cat.
Mark Twain - Notebook, 1894

Offline TwoTired

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Re: cb750f cam/valve spring question
« Reply #9 on: March 06, 2010, 11:12:20 AM »
What about the keepers on the retainer?
The stronger springs tends to make these fail, no?
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Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: cb750f cam/valve spring question
« Reply #10 on: March 06, 2010, 11:30:43 AM »
Well so far I haven't had that problem. The engine is coming down in the next week or so and I'll look for situations.
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As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline bucky katt

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Re: cb750f cam/valve spring question
« Reply #11 on: March 06, 2010, 03:15:22 PM »
i'm not going to take the chance. i'll wait to put the cam in until i have the titanium retainers. when i re-torque the head bolts next week i will put the fat cat vintage cycles adjustable cam sprocket in though and use their degree wheel as well. i''m not going to rush to do a modification then dislike the results later on down the road.
« Last Edit: March 06, 2010, 04:27:07 PM by bucky katt »
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Of all God's creatures there is only one that cannot be made the slave of the lash. That one is the cat. If man could be crossed with the cat it would improve man, but it would deteriorate the cat.
Mark Twain - Notebook, 1894
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